the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

2 ohm or not 2 ohm


Post ReplyPost New Topic
< Prev Topic Next Topic >
Steven Kephart 
Platinum - Posts: 1,737
Platinum spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spaceThis member consistently provides reliable informationspace
Joined: November 06, 2003
Location: Oregon, United States
Posted: June 17, 2007 at 12:58 AM / IP Logged  
duct tape wrote:

my point is...why would you pay money for a sub amp, then run it at 4 ohms, when it is designed to give full power at 2 ohms?  seems like a waste of money to me.   if you guys like to use half of your amp's potential, great, go for it, its your money

So you think that someone is wasting money if they don't load down their amplifier to it's lowest stable impedance?  So what do you say to people with a single 4 ohm sub?  After all 4 ohm stable sub amps are few and far between.  Do you require them to go out and purchase another sub to drop the impedance, or even swap subs?  Now who is wasting money?

duct tape wrote:
since you guys like to talk about cars so much....would you purchase a car that could hold 8 people, and only fill it up with 4 people?  that would be a waste of money, now wouldnt it?

Are you familiar with America's obsession with the SUV?  Do you really think that all those SUV's on the road are owned by families who are able to fill the seats up?  Heck, my car usually only has one person in it and it has 4 seats. 

There are advantages to running an amplifier at a higher impedance.  You will have less heat as Dyohn already mentioned, lower distortion, and less stress on the electrical system. 

3000dclass 
Copper - Posts: 50
Copper spacespace
Joined: June 05, 2007
Posted: June 17, 2007 at 3:57 AM / IP Logged  
Yes I should clarify the speakers situation.
I actually havent bought any speakers yet, but I believe I am going to buy two 15" JBL GTO1504D, which is the dual 4ohm sub, they also have the same thing bout offered as dual 2ohm.
   Now the reason I was thinking running at 4 ohm off one of my amps is because 4 ohm would put out 750rms from the amp.
   The subs are rated at 300rms, 1200 peak, so I wouldnt have a need to run it at 2 ohm putting out twice as much power.
Unless I buy three, or four maybe, of these 15" JBL subs, then 2 ohm would make more sense i guess.
I just wish I could afford some subs that could handle all my 3000 watts, oh well patience is a virtue.
One Rockford Fosgate 1500.1bd amp kicks serious ***!
I hade it hooked up from the repair shop yesterday to two 12" JL Audio W3 subs in a ported box at the speaker shop hooked up at 2 ohms, it when the sales guy was messing around with the gain, I could clearly hear a couple of times the amp putting out to much power for those poor subs to handle, and distortion city! Just wanted to share that cus Im very impressed with this product, and would recommend this amp to anyone needing plenty of power!
I also agree with that statement of running cooler is better, and keeps distortion away better, and Im all about distortion free music.
But I also would like to be able to use all available power I have, bet I could level a house if I had the money to drop on some higher end/price subs.
duct tape 
Copper - Posts: 125
Copper spacespace
Joined: May 18, 2006
Location: United States
Posted: June 17, 2007 at 7:06 AM / IP Logged  
Steven Kephart wrote:

So you think that someone is wasting money if they don't load down their amplifier to it's lowest stable impedance?  So what do you say to people with a single 4 ohm sub?  After all 4 ohm stable sub amps are few and far between.  Do you require them to go out and purchase another sub to drop the impedance, or even swap subs?  Now who is wasting money?

if he has the equipment, thats one thing.  but i would never sell a customer a mono subamp that is stable to 2 or 1 ohm, and then sell a single 4 ohm subwoofer, unless the customer planned on buying another sub at a later date.  that would be a waste of an amp. 

Steven Kephart wrote:
Are you familiar with America's obsession with the SUV?  Do you really think that all those SUV's on the road are owned by families who are able to fill the seats up?  Heck, my car usually only has one person in it and it has 4 seats. 

i'm very familiar with that obsession....it sounds like a mismatch to me, just like a 4 ohm sub on a mono sub amp.....

Steven Kephart wrote:
There are advantages to running an amplifier at a higher impedance.  You will have less heat as Dyohn already mentioned, lower distortion, and less stress on the electrical system. 

if you can tell on a mono sub amp, the distortion difference between a 2 and 4 ohm load, then you must have some very fine tuned ears. i understand that you will get less heat, but if the amp is designed for a lower impedance, then it should not be an issue.  if you want less stress on your electrical system, then dont buy an amp that is more than you need anyways.   

i really find it amazing that you guys cant understand my logic in this...is it because i dont have a thousand posts here and a bunch of icons next to my name, that you guys feel that my opinion is wrong?  i guarantee you, the rest of the car audio world is with me on this one....

DYohn 
Moderator - Posts: 10,740
Moderator spaceThis member has made a donation to the12volt.com. Click here for more info.spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: April 22, 2003
Location: Arizona, United States
Posted: June 17, 2007 at 9:27 AM / IP Logged  

Duct tape no one said you were wrong.  You just simply did not answer the question, and now you are getting belligerent about it.  Chill out.

I completely disagree with you, however, that it is somehow a "waste" to not run your gear full out all the time.  It is simply a matter of choice and trade-offs.  If someone wants the highest SQ possible from their gear and they are concerned about longevity, using higher impedance loads is a good thing to do.  If someone simply wants things to get as loud as possible, the lowest impedance load is the way to go.  Different strokes is all it is.

Me, I have used a DVC 4-ohm sub specifically so I can operate at 8-ohms many times.  In fact right now I have two 4-ohm SVC subs in series for an 8-ohm load in my car.  It's all about keeping things clean, doing what's best for the amp, and balancing the overall acoustic output of a system to create the effect I want in my vehicle. 

Support the12volt.com
haemphyst 
Platinum - Posts: 5,053
Platinum spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: June 17, 2007 at 10:43 AM / IP Logged  
duct tape, no one is saying that you are wrong, but it DOES sound to me as if you are saying the WE are wrong, also, (and repeatedly) because we don't exactly agree with you. We DO encourage spirited debates here, you've been here long enough to have seen one or two, I'd bet, but we all respect everybody's opinions, we always have.
DYohn and Steven have both expressed the pros and cons of running an amplifer at higher vs. lower impedances. Here is really what it boils down to:
Lower impedance
Pros:
More power
Higher SPL
Cons:
More total heat
More distortion
Lower damping factor
Lower efficiency
Shortened electronics life
Higher impedance
Pros:
Less total heat
Less distortion
Higher damping factor
Higher efficiency
Longer electronics life
Cons:
Less power
Lowered SPL
Those are all concrete and PROVABLE differences, (with the possible exception of the damping factor thing...) and to my eyes, the higher impedance load seems to be the better choice. The difference in sheer SPL output in running a 4 ohm load, vs a 2 ohm load is ONLY 3dB, (which in a competition is a HUGE number, especially when winners go home with a .1dB advantage, but) in a daily driver, that won't be noticed as a loss; and really, the improved fidelity due to lowered distortion and improved control over the woofers will most likely be perceived as a substantial benefit.
The big one for me, (actually the big two, the first being the distortion thing... oh, and the damping factor thing. 2 ohm or not 2 ohm - Page 2 -- posted image.) is the efficiency. For a lower impedance, there is MORE HEAT PROPORTIONATELY produced for a given output. This means that if an amplifier is 60% efficient at 4 ohms, (a typical Class AB number) it could be as low as 50% efficient at 2 ohms. (Also a fairly typical number, in the case of Class AB) It doesn't maintain it's efficiency at all loads.    More proportionate stress on the electrical system... Less (or lower) efficiency is a bad thing. Class D amplifers suffer the SAME efficiency drop, although they DO start at a higher reference efficiency, true.
Even IF an amplifier is designed to run safely at a given load, a one degree rise in temperature will cause as much as a 25% reduction in total life of ANY electronic device, such as a transistor. Capacitors are even MORE sensitive to it; they're more like 50 to 60%. Doesn't it make even more sense to reduce the operating temperature of any electronic component, now? Obviously, the devices are RATED for such operating temperatures, but the rule above also applies for a REDUCTION of temperature. Run a device one degree COOLER, and it will last up to 25% LONGER... THERE'S your money savings!
You also mentioned that the entire car audio industry would agree with you. I personally take exception to that, and I can get you in contact with two engineers (ok, one engineer and one engineer intern 2 ohm or not 2 ohm - Page 2 -- posted image.) at Harman International in Northridge, CA, that DO NOT disagree with me or the other accepted (and NOT wrong) views on this forum. I guarantee you, that I do not disagree with you, and I DO understand your logic, but it is NOT the only view, and we could throw that back at you as well...
(How's that? (And that person knows to whom I am referring...))
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
tcss 
Silver - Posts: 1,623
Silver spacespace
Joined: June 07, 2004
Location: United States
Posted: June 17, 2007 at 2:40 PM / IP Logged  
David, you must have still been in transit (or drooling on your new amps) when this discussion was going down.LOL.  As usual your argument was complete and correct. I, as a dealer in car audio for 26 years, agree 100%.
There is no such thing as free installation!
Vestax 
Member - Posts: 13
Member spacespace
Joined: January 05, 2005
Location: United States
Posted: June 17, 2007 at 11:35 PM / IP Logged  

I'm with Duct Tape with this one. He's simply trying to help the OP to get the most out of his amp. I don't know how anyone can preach to buy your amps and don't put it at the lowest impedance because the cons produced are yes, proveable, but most of the time it is inaudible and doesn't really make a difference. Hell, you're not even calculating everything else in his set up and you don't know how the OP's electrical system is. What's wrong with a little headroom and gains manipulation? Just curious, out of all the enthusiast and consumers in this money pit,  who's buying their sub amps to put it at higher impedance? Very little I would guess. And it's probably those same home audio guys who are buying $500 speakers wires to put it in their cars.

Oh BTW, people gotta stop bringing in other professionals to back their statement up. We have the same engineers saying to keep your RCA's and power wire separate. I pretty sure the majority installers know how questionable that logic is... when their guilty of doing that but yet to get noise. "Hey, I've been doing this for 20 years, I know what I'm doing." Yeah you could be doing it wrong for 20 years. LMAO!! :D

USUC World Champion - Stock System Class, Super Street Division. Special Edition Bose 26 piece speaker system with enhanced ported tweeters. 89.2 db Legal, 89.6 db Outlaw
haemphyst 
Platinum - Posts: 5,053
Platinum spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: June 18, 2007 at 12:03 AM / IP Logged  
Get the most WHAT? Heat? Distortion? Short lived electrical components? Did you read the last post I put up?
Vestax, did you even bother to read all of the thread? You are now doing the same thing duct tape was doing, and basically telling us we are wrong. Are we, in fact, WRONG, or are you simply stating your opinion? I already said that he WASN'T wrong, yet here you come into the thread, and effectively say that we ARE wrong.
Headroom, at the expense of distortion and short-lived electronics is not a gain.
As DYohn asked (and answered) of duct tape, did you answer the question? No, in fact, he didn't. Now, I will ask the same of you: Did you actually answer the question? No, again...
I'll paraphrase the question AGAIN.
3000dclass wanted to know if there was any truth to the (potential) urban myth that running an amplifier with 4 ohms, instead of the maximum stable load of 2 ohms, is easier on the amplifier... We (DYohn, Steven, and I) all answered the question, (and even backed some of our answers with researchable, provable scientific, and hard facts) as to why it IS easier on the amplifier to run with a higher impedance.
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
aznboi3644 
Gold - Posts: 2,600
Gold spaceThis member consistently provides reliable informationspace
Joined: May 01, 2006
Location: United States
Posted: June 18, 2007 at 12:36 AM / IP Logged  
Right now I have an eD Nine.1 amp...stable down to 1 ohm but am running a SVC 8 ohm sub. I feel no waste in power or money.
Vestax 
Member - Posts: 13
Member spacespace
Joined: January 05, 2005
Location: United States
Posted: June 18, 2007 at 12:50 AM / IP Logged  

haemphyst wrote:
Get the most WHAT? Heat? Distortion? Short lived electrical components? Did you read the last post I put up?
Vestax, did you even bother to read all of the thread? You are now doing the same thing duct tape was doing, and basically telling us we are wrong. Are we, in fact, WRONG, or are you simply stating your opinion? I already said that he WASN'T wrong, yet here you come into the thread, and effectively say that we ARE wrong.
Headroom, at the expense of distortion and short-lived electronics is not a gain.
As DYohn asked (and answered) of duct tape, did you answer the question? No, in fact, he didn't. Now, I will ask the same of you: Did you actually answer the question? No, again...
I'll paraphrase the question AGAIN.
3000dclass wanted to know if there was any truth to the (potential) urban myth that running an amplifier with 4 ohms, instead of the maximum stable load of 2 ohms, is easier on the amplifier... We (DYohn, Steven, and I) all answered the question, (and even backed some of our answers with researchable, provable scientific, and hard facts) as to why it IS easier on the amplifier to run with a higher impedance.

Okay you got me there haemphyst. You're right... I didn't really read the first question thoroughly. You guys are answering the question that the OP's asking. I apologize. I jumped the gun and saw a lot of bickering. LMAO!

USUC World Champion - Stock System Class, Super Street Division. Special Edition Bose 26 piece speaker system with enhanced ported tweeters. 89.2 db Legal, 89.6 db Outlaw
Page of 3

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Tuesday, December 6, 2022 • Copyright © 1999-2022 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer